Best Time to Fly IAH to STL: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
420 flights were scheduled from Houston (IAH) to St. Louis (STL) in the last 12 months, and 75.4% of those that flew arrived on time, 2.2 points below the US average of 77.6%.
Among 2 airlines, United Airlines led with 75.9% on time and SkyWest Airlines was last with 72.7%.
Over 24 months, Tuesday was the most reliable day (81% on time) and June the worst month (51%).
The cancellation rate was 0.7% (US average 1.8%).
IAH to STL on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| United Airlines | 75.9% | 56 min | 0.8% | 354 |
| SkyWest Airlines | 72.7% | 70 min | 0.0% | 66 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to STL
On-time arrival % by scheduled departure hour (local time), 1,092 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 7am–8am | 71.9% | 0.0% | 32 |
| 8am–9am | Limited data | 5 | |
| 12pm–1pm | 75.6% | 0.8% | 120 |
| 1pm–2pm | 83.3% | 2.9% | 68 |
| 2pm–3pm | 69.9% | 0.0% | 206 |
| 4pm–5pm | 75.0% | 0.0% | 65 |
| 5pm–6pm | Limited data | 18 | |
| 6pm–7pm | 76.9% | 0.0% | 39 |
| 7pm–8pm | 77.6% | 2.3% | 128 |
| 8pm–9pm | 72.0% | 0.8% | 359 |
| 9pm–10pm | 80.4% | 1.9% | 52 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAH to STL
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 25 | ||
| Christmas & New Year (Dec 20 - Jan 3) | Limited data | 30 | ||
| Summer peak (Jun 15 - Aug 15) | 67.6% | -7.2 pts | 0.0% | 148 |
| All other days | 74.8% | — | 1.0% | 889 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).